George Zimmerman's brother compares Ga. baby killer to Trayvon Martin

(CBS) - The older brother of George Zimmerman, the man accused of killing Florida teenager Trayvon Martin, posted an image on Twitter comparing the deceased teen to an alleged Ga. baby-killer.

On March 24, Robert Zimmerman, Jr., tweeted an image of Martin alongside one of De'Marquise Kareem Elkins, the 17-year-old accused offatally shootingone-year-old Antonio Santiago in his stroller on March 21.

Zimmerman's brother George shot and killed 17-year-old Trayvon Martin in Feb. 2012. He's charged with second-degree murder and has pleaded not guilty, claiming he shot the unarmed teen in self-defense.

Robert Zimmerman sent the tweet multiple times. It featured side-by-side photographs and the words "A picture speaks a thousand words. Any questions?" Zimmerman addressed the tweet specifically to the NAACP, filmmaker Michael Moore, the National Rifle Association, and Anthony Cumia of the Opie and Anthony show, among others.

In one of many subsequent tweets, Zimmerman stated: "1 of those pics is a person who may have murdered @ point-blank range, the other: a person who gave every indication they prob would've."